What is the cause of oral pain in a 40-year-old male who was prescribed amoxicillin (amoxicillin) last week?

From the Guidelines

For a 40-year-old male with persistent mouth pain despite being prescribed amoxicillin last week, I strongly recommend seeking prompt medical reevaluation to rule out antibiotic-resistant infection, incorrect initial diagnosis, or non-infectious causes. Given the patient's recent amoxicillin use, the guidelines suggest considering switch therapy options if there's no improvement or worsening after 72 hours 1. The patient's symptoms could be due to various conditions such as dental abscess, oral candidiasis (thrush) as a side effect of the antibiotics, viral stomatitis, or temporomandibular joint disorder. While waiting for medical attention, the patient can use over-the-counter pain relievers like acetaminophen or ibuprofen (400-600mg every 6 hours with food) and saltwater rinses (1/2 teaspoon salt in 8 ounces warm water) several times daily. Avoiding spicy, acidic, or hard foods may help reduce discomfort. If symptoms worsen with fever, difficulty swallowing, or breathing problems, emergency care should be sought immediately. Completing the full course of prescribed amoxicillin remains important unless directed otherwise by a healthcare provider, as stopping antibiotics prematurely can lead to resistant infections 1. Some key considerations for the healthcare provider include:

• Reevaluating the patient's condition to determine the best course of action
• Considering alternative antibiotic therapies, such as amoxicillin/clavulanate, gatifloxacin, levofloxacin, or moxifloxacin, if the initial treatment was ineffective 1
• Evaluating the patient's risk factors for infection with resistant organisms, such as recent antibiotic use, to guide antibiotic selection 1.

From the FDA Drug Label

The most common adverse reactions (greater than 1%) observed in clinical trials of amoxicillin for oral suspension were diarrhea, rash, vomiting, and nausea. Miscellaneous:Tooth discoloration (brown, yellow, or gray staining) has been reported. Most reports occurred in pediatric patients. Discoloration was reduced or eliminated with brushing or dental cleaning in most cases.

Mouth pain in a 40-year-old male who was given amoxicillin last week may be related to tooth discoloration, which is a reported adverse reaction of amoxicillin 2. However, this is more commonly seen in pediatric patients.

• Other possible causes of mouth pain are not directly mentioned in the drug label.
• It is essential to consider other potential causes of mouth pain and evaluate the patient's symptoms further. 2

From the Research

Patient Profile

• 40-year-old male
• Experiencing mouth pain
• Given amoxicillin last week

Relevant Studies

• A study published in 2021 3 compared different antibiotic treatments for group A streptococcal pharyngitis, including amoxicillin, and found that the effectiveness of antibiotics increases in people with positive throat swabs for group A beta-haemolytic streptococci (GABHS)
• Another study from 2010 4 found high resistance against clindamycin, metronidazole, and amoxicillin in Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans isolates of periodontal disease, suggesting that antibiotic susceptibility testing is necessary to determine efficacy of antimicrobial agents

Potential Causes of Mouth Pain

• Periodontal disease, which may be caused by bacteria such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans 4
• Group A streptococcal pharyngitis, which can be treated with antibiotics such as amoxicillin 3
• Other potential causes, such as drug-induced vasculitis, which can be caused by various pharmaceutical agents, including antibiotics 5

Considerations for Treatment

• The study published in 2021 3 found that cephalosporins and macrolides may be effective alternatives to penicillin for treating group A streptococcal pharyngitis
• The study from 2010 4 suggested that moxifloxacin and amoxicillin/clavulanic acid may be effective against Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans isolates of periodontal disease
• Metronidazole, which has strong activity against most anaerobes and certain parasites, may also be considered as a treatment option 6